Example Ant build task to check for SASS debug info in CSS files, and fail a build if it finds some.

sass-debug-info-check-build.xml

<?xml version="1.0" encoding="UTF-8"?>

<project name="sass-debug-info-check" default="default" basedir="./">
    
	<taskdef resource="net/sf/antcontrib/antlib.xml">
	  <classpath>
		<pathelement location="${basedir}/tools/ant-contrib/ant-contrib-0.3.jar"/>
	  </classpath>
	</taskdef>
	
	<!-- Provide a css-check.properties file to override the default property settings...		
	cssDir = ${basedir}../path/to/your/built/site/files
	cssIncludes = **/*.css
	-->
	
	<property file='${basedir}/css-check.properties'/>
	<property name='cssDir' value='${basedir}'/>
	<property name='cssIncludes' value='**/*.css'/>
 
	
	<target name="default" depends="checkCSSForSASSDebugInfo">
		<echo>checkCSSForSASSDebugInfo - All is well, there's no naughty SASS action here!</echo>
	</target>
	
	<target name="checkCSSForSASSDebugInfo">	
	
		<echo>Testing all files matching ${cssIncludes} within ${cssDir}</echo>
		
		<!-- select all css files to be checked -->
		<fileset id="cssToCheck" dir="${cssDir}" includes="${cssIncludes}">
			<!-- checking for occurances of the string "@media -sass-debug-info" in our css... -->
			<contains text="@media -sass-debug-info"/>
		</fileset>
		
		<!-- convert matches to a string for logging, seperate with a newline pathsep -->
		<pathconvert pathsep="&#10;" property="badCSSMatches" refid="cssToCheck"/>
		
		<!-- set haveBadCSS property true when badCSSMatches length > 0 -->
		<condition property="haveBadCSS">
			<length string="${badCSSMatches}" trim="true" when="greater" length="0" />
		</condition>
		
		<!-- if haveBadCSS - log the offending files and fail the build -->
		<if>
			<equals arg1="${haveBadCSS}" arg2="true" />
			<then>
				<echo level="error">Found SASS debug info in the following files:</echo>
				<echo level="error">${badCSSMatches}</echo>
				<fail message="Found SASS debug info in the CSS!" />		
			</then>
			<else>
				<echo>No SASS debug info found in the tested CSS files.</echo>
			</else>
		</if>
		
	</target>
</project>